Tobacco smoke filter

ABSTRACT

A filter is provided which is adapted to the affixed to one end of a tobacco rod. The filter is formed of three laminae defining a sleeve unit which is in sealing encompassing relation with a smoke barrier piece. The outer lamina is of smoke impervious thin sheet material, the intermediate lamina is of thin sheet material with a plurality of longitudinally extending elongated slots formed therein, and the inner lamina is of thin sheet material provided with a plurality of perforations arranged in sleeveencircling relation and in registration with the slots of the intermediate lamina. As smoke is drawn through the filter, it is caused to pass through the perforations at a high velocity whereupon it impinges against an obstructing surface disposed in close proximity to the perforations.

United States Patent [72] Inventor Joseph H. Sherrill Winston-Samlem, N.C. [21] Appl. No. 837,669 [22] Filed June 30, 1969 [45] Patented May 11, 1970 [73] Assignee R. J. Reynolds Tobacco Company Winston-Salem, N.C.

[54] TOBACCO SMOKE FILTER 10 Claims, 8 Drawing Figs.

[52] US. Cl l3l/l0.5, 131/201,131/210, 131/212 [51] Int. Cl A24d 01/04,

A24f0l/08, A24f0l/l6 [50] Field of Search 131/l0.5, 201, 210; 131/212, 213, 216, 218, 261 (B); 131/198, 10.3

[56] References Cited UNITED STATES PATENTS 1,582,971 5/1926 Conley 131/201 2,737,187 3/1956 Kokkinos 131/198 Primary ExaminerSamuel Koren Assistant Examiner.lohn F. Pitrell Attorney-Pendleton, Neuman, Anderson & Williams ABSTRACT: A filter is provided which is adapted to the affixed to one end of a tobacco rod. The filter is formed of three laminae defining a sleeve unit which is in sealing encompassing relation with a smoke barrier piece. The outer lamina is of smoke impervious thin sheet material, the intermediate lamina is of thin sheet material with a plurality of longitudinally extending elongated slots formed therein, and the inner lamina is of thin sheet material provided with a plurality of perforations arranged in sleeve-encircling relation and in registration with the slots of the intermediate lamina. As smoke is drawn through the filter, it is caused to pass through the perforations at a high velocity whereupon it impinges against an obstructing surface disposed in close proximity to the perforations.

PATENTEU MAY! 1 I97! SHEET 1 BF 2 4% rug PATENTEDHAYHIQII I 3577.996

suznaurz I Joseph H. Sherri/l TOBACCO SMOKE FILTER BACKGROUND OF THE INVENTION Various filters adapted primarily for use in filter cigarettes have heretofore been proposed; however, because of their structural designs, they are either difficult and slow to assemble, require a large number of component parts, certain of which are of costly construction, or are ineffective in removing the solid and/or liquid particles entrained in the smoke as it circulates through the filter.

SUMMARY OF THE INVENTION Thus, it is an object of this invention to provide a filter which is not possessed of the aforenoted shortcomings associated with the prior structures.

It is a further object of this invention to provide a filter which may be readily assembled by automatic equipment, the function and operation of which are well understood in the cigarette making art.

Further and additional objects will appear from the description, accompanying drawings and appended claims.

In accordance with one embodiment of the invention, a filter is provided which comprises a sleeve unit formed of three laminae and affixed to the downstream end of a tobacco rod, and a smoke barrier piece disposed within the sleeve unit and in sealing engagement therewith. The sleeve unit includes an outer lamina formed from a thin sheet of smoke impervious material; an intermediate lamina formed from thin sheet material provided with a plurality of longitudinally extending, elongated substantially parallel slots; and an inner lamina formed of thin sheet material provided with a plurality of perforations arranged in sleeve unit-encircling relation. The inner and outer laminae cooperate with the slots of the intermediate laminae to form a plurality of shallow passageways. EAch passageway is in communication with a perforation of the inner lamina.

As smoke is drawn through the filter, it is caused to pass through the passageways and the perforations and is emitted from the latter at a high velocity. Subsequent to passing through the perforations and while flowing at a high velocity, the smoke impinges against an adjacent obstructing surface causing solid and/or liquid particles entrained in the smoke to be deposited thereon.

For a more complete understanding of the invention, reference should be made to the drawings wherein:

FIG. 1 is a fragmentary perspective view of a filter cigarette embodying one form of the improved filter; portions of the latter being partially removed so as to expose the components thereof.

FIG. 2 is a fragmentary side elevational view of the cigarette of FIG. 1 and showing the filter end in substantially longitudinal section.

FIG. 3 is a perspective top view of the smoke barrier piece comprising a part of the filter of FIG. 1.

FIG. 4 is a fragmentary perspective top view of a web of material from which the intennediate lamina is formed.

FIG. 5 is similar to FIG. 4 but showing the web of material for the inner lamina.

FIG. 6 is similar to FIG. 1 but showing a modified form of the improved filter.

FIG. 7 is similar to FIG. 2 but showing the filter of FIG. 6.

FIG. 8 is a fragmentary perspective schematic view showing a part of the automatic filter-forming equipment and the improved filter at a predetennined stage of assembly.

i Referring now to the drawings and more particularly to FIG. 1, a filter cigarette 10 is shown which includes a tobacco rod 11 of conventional design and having a lightable end 11a and a downstream end 11b, and one form 12 of the improved filter affixed to the rod downstream end. The filter 12 in the illustrated embodiment includes a smoke barrier piece 13 and a laminated sleeve unit 14 which sealingly encompasses the piece.

The barrier piece 13, as seen more clearly in FIGS. 2 and 3, may be formed by extrusion, injection molding or the like from a smoke impervious material such as plastic or paper pulp. The upstream end of piece 13 is in the form of a disc 13a, the periphery of which is in sealing engagement with the inner lamina 15 forming apart of the sleeve unit 14. The disc 13a is preferably disposed in close proximity with the rod end 11b. Extending downstream from disc 13a is an annular rodlike segment 13b which is of reduced diameter as compared to disc 13a; however, the periphery of the segment is in close proximity with respect to the interior surface of the inner lamina. A second annular rodlike segment 130 of further reduced diameter is provided which extends axially downstream from segment 13b. Segment 13c terminates in a second disc 13d which is disposed adjacent the free, or smokeemitting, end of the filter. As seen in FIG. I, the outer periphery of second disc 13d is serrated so as to form a plurality of symmetrically arranged valleys 16. In lieu of being serrated, the outer periphery may be knurled, grooved or otherwise fonned so that when the outer periphery is encompassed by inner lamina 15, a plurality of passageways will be defined through which the smoke will be drawn prior to being emitted from the filter free end.

Where the barrier piece 13 is extruded, the exterior configuration of the extrusion initially conforms substantially to the outer periphery of disc 13a and then the rod segments 13bc and disc 13d are subsequently shaped in a manner well known in the forming and extruding art.

In addition to the inner lamina 15, the sleeve unit 14 includes an intermediate lamina 17 and an outer lamina 18. All of the laminae are preferably formed, of suitable paper stock. Prior to the laminae being brought together so as to form sleeve unit 14, the inner lamina 15 has a plurality of perforations 20 formed therein, see FIG. 5. Perforations 20 are arranged in longitudinally spaced sets I and II. Each set may comprise either one row or two longitudinally spaced, substantially parallel rows A and B of perforations. In either structure, each row encircles the inner lamina when the sleeve unit 14 is formed. In the filter 12 shown in FIGS. 1 and 2, only one row of perforations is utilized. The assembly of the filter components will be discussed more fully hereinafter.

The intermediate lamina 17, prior to being assembled with the other laminae, has formed therein longitudinally spaced portions, each of which is provided with a plurality of narrow, longitudinally extending slots 21 arranged in substantially parallel relation. The length of each slot is such that where two rows of perforations are utilized in a filter, the corresponding perforations in the rows A and B are both in communication with a given slot when the two lamina are assembled. The modified filter 12A shown in FIG. 7 illustrates an improved filter where two rows of perforations are utilized. Filter 12A will be described more fully hereinafter. Where only one row of perforations is used, as in the case of filter 12, see FIGS. 1 and 2, each perforation comprising the row is in registration and in communication with the downstream end of a given slot.

The segments 22 which separate adjoining slots 21 serve as bracing ribs between the inner and outer laminae 15 and 18,

respectively, when the sleeve unit 14 is formed.

The outer lamina 18 is of smoke impervious material, such as the conventional tipping, and serves a dual function (a) it encompasses the end 11b of the tobacco rod 11 and affixes the filter l2 thereto; and (b) it cooperates with the inner lamina l5 and the slots 21 of intermediate lamina 17 to form a pluraliperforations 20. By reasonof the sizing of the perforations 20, the smoke passes therethrough at a high velocity and impinges against the outer peripheral surface of segment 13b whereupon the solid and/or liquid particles entrained in the smoke are deposited on the segment surface.

After impinging against the segment surface, the smoke is deflected and ultimately passes through the plurality of passageways defined by the valleys 16 formed in the outer periphery of barrier piece disc 13d. The reduction in diameter size of segment 13c with respect to that of segment 13b minimizes the pressure drop which occurs as the smoke passes through the filter.

ln the modified filter 12A shown in FIGS. 6 and 7, a smoke impervious ball or sphere 23 is substituted for the barrier piece 13 and in addition the inner lamina 15 having two rows A and B of perforations is utilized. The ball 23 is in sealing contact with the interior surface of lamina 15. The line of contact between the ball and the inner lamina occurs intermediate the rows A and B of perforations 20. Thus, the smoke upon leaving tobacco rod end 11b is blocked by the all 23 which is spaced from the rod end and is forced to flow outwardly at a high velocity from a space 24 through the row A of perforations and into the shallow passageways defined by the slots 20. Due to the shallowness of the passageways and the high velocity of the smoke emitted from the row A of perforations 20, the smoke impinges against the interior surface of the outer lamina 18 and the solid and/or liquid particles entrained in the smoke are deposited thereon. As the smoke flows through the shallow passageways, it circumvents the ball 23. Upon the smoke reaching the downstream ends of the passageways, it is deflected inwardly through the row B or perforations into a space 25 formed downstream of ball 23 and then out through the free end of the filter 12A. If desired a plug, not shown, of suitable filter material, e.g. cellulose acetate and/or charcoal, may be inserted within either space 24 or 25, or both.

In assembling the filter 12, an extruded bar 26, see FIG. 8, which comprises a plurality of integrally connected barrier pieces 13 arranged in inverted end-to-end relation, is fed at a predetermined rate in an axial direction by suitable mechanical means, not shown. At a predetermined station of travel the bar 26 is engaged and subtended by a composite web 27 which comprises a first lamina web 15 of the type shown in FIG. and a second lamina web 17' shown in FIG. 4.

First lamina web in an unperforated state, is initially withdrawn from a bobbin or spool 27 of conventional design and is then fed between a pair of complemental perforating rolls 28a and b. From the perforating rolls the web moves through a blue applicator 30.

The lamina web 17', on the other hand, in an unslotted state, is withdrawn from a bobbin or spool 31 of conventional design and then over an idling roll 32 so that the web will sub stantially conform to the periphery of a suitable drum 33. Dlsposed at a predetermined location adjacent the periphery of drum 33 is a rotating cutter of slotter 34 of conventional design which cooperates with the drum periphery so as to form the plurality of slots 21 in the arrangement shown in FIG. 4. Angularly spaced downstream from cutter 34 and disposed adjacent the periphery of drum 33 is a brush or roller 35 which is power driven and revolves against the slotted web so as to remove the slotted blanks from the moving web. After passing the brush 35, the web 17' is brought into bonding engagement with a glue surface of web 15' and then the two laminae are brought into encompassing relation with the rod 26 by the forming unit 36. AFter leaving the unit 36, the laminae-encompassed rod 26 is subsequently cut into segments which are then affixed to the ends of the tobaccorods in a manner well understood in the cigarette-making art.

It is obvious that the shape and size of the smoke barrier pieces may very substantially from those illustrated and described without departing from the scope of this invention.

Thus, it will be seen that a filter for cigarettes or the like has been provided which is capable of high speed production and is compatible with the conventional present day equipment used in making cigarettes and cigarette filters. The improved filter is of simple, inexpensive construction and is effective in removing solid and/or liquid particles nonnally entrained in tobacco smoke.

lclaim:

l. A filter for use with a tobacco rod having lightable and downstream ends, said filter comprising an outer smoke impervious sleeve unit formed from sheet material and adapted to be affixed to the downstream end of the tobacco rod;.an interrnediate sleeve unit formed from sheet material and encompassed by and in contact with the interior surface of said outer unit, said intermediate sleeve unit having a plurality of elongated longitudinally extending segments arranged in spaced relation; an inner sleeve unit formed from sheet material and encompassed by and in contact with the interior surface of said intermediate unit, said inner unit being provided with a plurality of small perforations arranged in encircling relation with respect to said inner unit, said perforations being aligned with the spaces formed between the segments of said intermediate unit; and a smoke barrier piece encompassed by said inner sleeve unit, said barrier piece having a portion thereof disposed adjacent to but spaced from said perforations and in sealing engagement with said inner unit interior surface; one of said outer sleeve unit and said barrier piece forming an obstructing surface; said outer unit, the elongated segments of said intermediate unit, and said inner unit cooperating to form a plurality of elongated shallow passageways through which smoke is adapted to flow; in addition to flowing through said passageways, the smoke upon being drawn through said filter flows at a high velocity through said perforations and impinges upon said obstructing surface whereby particles entrained in the smoke are deposited thereon.

2. The filter of claim 1 wherein said perforations are in communication with the upstream ends of said passageways and the particles deposition occurs on the interior surface of said outer sleeve unit defining said passageways.

3. The filter of claim 1 wherein said inner sleeve unit is provided with two sets of perforations disposed in longitudinally spaced relation, the perforations of each set being arranged in sleeve unit-encircling relation, one set of perforations communicating with said passageways and disposed upstream of said barrier piece and the other set of perforations communicating with said passageways and disposed downstream of said barrier piece; the smoke drawn through said filter passing at a high velocity through said first set of perforations into said shallow passageways and effecting particle deposition on the interior surface of said outer sleeve unit defining said passageways.

4. The filter of claim 1 wherein said barrier piece includes a second portion disposed downstream of said first mentioned portion, said barrier piece second portion being spaced inwardly of, but in close proximity to, said perforations and functioning as said obstructing surface against which the high velocity smoke impinges.

5. The filter of claim 4 wherein said barrier piece includes a third portion disposed downstream of said second portion, the periphery of said third portion cooperating with the interior surface of said inner sleeve unit to form a plurality of second passageways.

6. The filter of claim 5 wherein said barrier piece is of one piece construction.

7. The filter of claim 1 wherein said barrier piece comprises a spherical member which is in sealing engagement with the interior surface of said inner sleeve unit.

8. A filter for use with a tobacco rod having lightable and downstream ends, said filter comprising three laminae of thin sheet material shaped to form a sleeve unit for affixing to the tobacco rod downstream end, and a smoke barrier piece disposed within said sleeve unit and in sealing engagement with an inner lamina fonning said sleeve unit; the laminated sleeve unit comprising a smoke impervious outer lamina, an intermediate lamina provided with a plurality of longitudinally extending elongated slots arranged in symmetrically spaced relation, and said inner lamina provided with a plurality of perforations arranged in sleeve unit-encircling relation and spaced from said barrier piece, said inner and outer laminae cooperating with said elongated slots to form a plurality of shallow passageways which circumvent said barrier piece, each perforation of said inner lamina being in communication with a shallow passageway, one of said outer lamina and said barrier piece forming an obstructing surface smoke, upon being drawn through said filter, flowing through said perforations and said passageways and being emitted from said perforations at a high velocity whereupon the high velocity smoke impinges upon said obstructing surface causing particles entrained in the high velocity smoke to be deposited on said obstructing surface.

9. A smoke filter element adapted to be affixed to the downstream end of a tobacco smoking article which comprises a solid smoke barrier core piece having a generally cylindrical upstream end section, a generally cylindrical center section of lesser diameter, and a generally cylindrical downstream end section having essentially the same diameter as said upstream end section and having a plurality of longitudinally extending channels in the outer peripheral surface thereof; a sleeve encompassing said upstream and downstream end and center sections and defining an annular passageway with said center section and a plurality of longitudinal passageways with said channels; and a plurality of spaced smoke accelerating orifices in said sleeve in registry with said annular passageway.

10. A smoke filter adapted to be attached to the downstream end of a tobacco smoking article which comprises a core piece having a generally cylindrical upstream end section, a generally cylindrical center section of lesser diame-, ter and a generally cylindrical downstream end section having essentially the same diameter as said upstream end section and having a plurality of longitudinally extending channels in the outer peripheral surface thereof; a first smoke impervious sleeve encompassing said upstream and downstream end and center sections and defining an annular first passageway with said center section and a plurality of longitudinal second passageways with said channels; a second smoke impervious sleeve encompassing said first sleeve in spaced relationship thereto and defining therewith a third passageway radially spaced from said upstream end and center sections; a plurality of spaced smoke accelerating orifices in said first sleeve in registry with said center section; and a third sleeve interposed between said first and second sleeves downstream from said orifices providing a smoke barrier in said third passageway whereby smoke passing to said first and second passageways from said third passageway is diverted through said orifices.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 7 9 Dated May 11, 197].

Joseph H. Sherrill Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the page containing the Abstract, the patent date (Item 45) should be May ll, l97l and the last name of the Assistant Examiner should be Petrelli and insert be In line 1 of the Abstract, cancel "the In the Specification:

Column 2, line 6, "apart" should be a part 2 line 50, "lamina" should read laminae Column 3, line 20, 'all" should read ball 3, line 32, "or" should read of 3, line 57, "of" (second occurrence) should read 3, line 72, 'very" should read vary Column 4, line 25, cancel the semicolon and insert a comma Column 5, line 8, after "surface" insert a semicolon Signed and sealed this 21st day of December 1971.

(SEAL) Attest:

EDWARD M.FLE'ICHER,JR. ROBERT GOTTSCHALK Attesting Officer Acting Commissioner of Patents FORM PO-IOSO (10-69) USCOMM-OC 60376-969 ",5, GOVERNMENT PRINTING OFFICE I9? O3S6-334 

1. A filter for use with a tobacco rod having lightable and downstream ends, said filter comprising an outer smoke impervious sleeve unit formed from sheet material and adapted to be affixed to the downstream end of the tobacco rod; an intermediate sleeve unit formed from sheet material and encompassed by and in contact with the interior surface of said outer unit, said intermediate sleeve unit having a plurality of elongated longitudinally extending segments arranged in spaced relation; an inner sleeve unit formed from sheet material and encompassed by and in contact with the interior surface of said intermediate unit, said inner unit being provided with a plurality of small perforations arranged in encircling relation with respect to said inner unit, said perforations being aligned with the spaces formed between the segments of said intermediate unit; and a smoke barrier piece encompassed by said inner sleeve unit, said barrier piece having a portion thereof disposed adjacent to but spaced from said perforations and in sealing engagement with said inner unit interior surface; one of said outer sleeve unit and said barrier piece forming an obstructing surface; said outer unit, the elongated segments of said intermediate unit, and said inner unit cooperating to form a plurality of elongated shallow passageways through which smoke is adapted to flow; in addition to flowing through said passageways, the smoke upon being drawn through said filter flows at a high velocity through said perforations and impinges upon said obstructing surface whereby particles entrained in the smoke are deposited thereon.
 2. The filter of claim 1 wherein said perforations are in communication with the upstream ends of said passageways and the particles deposition occurs on the interior surface of said outer sleeve unit defining Said passageways.
 3. The filter of claim 1 wherein said inner sleeve unit is provided with two sets of perforations disposed in longitudinally spaced relation, the perforations of each set being arranged in sleeve unit-encircling relation, one set of perforations communicating with said passageways and disposed upstream of said barrier piece and the other set of perforations communicating with said passageways and disposed downstream of said barrier piece; the smoke drawn through said filter passing at a high velocity through said first set of perforations into said shallow passageways and effecting particle deposition on the interior surface of said outer sleeve unit defining said passageways.
 4. The filter of claim 1 wherein said barrier piece includes a second portion disposed downstream of said first mentioned portion, said barrier piece second portion being spaced inwardly of, but in close proximity to, said perforations and functioning as said obstructing surface against which the high velocity smoke impinges.
 5. The filter of claim 4 wherein said barrier piece includes a third portion disposed downstream of said second portion, the periphery of said third portion cooperating with the interior surface of said inner sleeve unit to form a plurality of second passageways.
 6. The filter of claim 5 wherein said barrier piece is of one piece construction.
 7. The filter of claim 1 wherein said barrier piece comprises a spherical member which is in sealing engagement with the interior surface of said inner sleeve unit.
 8. A filter for use with a tobacco rod having lightable and downstream ends, said filter comprising three laminae of thin sheet material shaped to form a sleeve unit for affixing to the tobacco rod downstream end, and a smoke barrier piece disposed within said sleeve unit and in sealing engagement with an inner lamina forming said sleeve unit; the laminated sleeve unit comprising a smoke impervious outer lamina, an intermediate lamina provided with a plurality of longitudinally extending elongated slots arranged in symmetrically spaced relation, and said inner lamina provided with a plurality of perforations arranged in sleeve unit-encircling relation and spaced from said barrier piece, said inner and outer laminae cooperating with said elongated slots to form a plurality of shallow passageways which circumvent said barrier piece, each perforation of said inner lamina being in communication with a shallow passageway, one of said outer lamina and said barrier piece forming an obstructing surface smoke, upon being drawn through said filter, flowing through said perforations and said passageways and being emitted from said perforations at a high velocity whereupon the high velocity smoke impinges upon said obstructing surface causing particles entrained in the high velocity smoke to be deposited on said obstructing surface.
 9. A smoke filter element adapted to be affixed to the downstream end of a tobacco smoking article which comprises a solid smoke barrier core piece having a generally cylindrical upstream end section, a generally cylindrical center section of lesser diameter, and a generally cylindrical downstream end section having essentially the same diameter as said upstream end section and having a plurality of longitudinally extending channels in the outer peripheral surface thereof; a sleeve encompassing said upstream and downstream end and center sections and defining an annular passageway with said center section and a plurality of longitudinal passageways with said channels; and a plurality of spaced smoke accelerating orifices in said sleeve in registry with said annular passageway.
 10. A smoke filter adapted to be attached to the downstream end of a tobacco smoking article which comprises a core piece having a generally cylindrical upstream end section, a generally cylindrical center section of lesser diameter and a generally cylindrical downstream end section having essentially the same diameter as said upstream end seCtion and having a plurality of longitudinally extending channels in the outer peripheral surface thereof; a first smoke impervious sleeve encompassing said upstream and downstream end and center sections and defining an annular first passageway with said center section and a plurality of longitudinal second passageways with said channels; a second smoke impervious sleeve encompassing said first sleeve in spaced relationship thereto and defining therewith a third passageway radially spaced from said upstream end and center sections; a plurality of spaced smoke accelerating orifices in said first sleeve in registry with said center section; and a third sleeve interposed between said first and second sleeves downstream from said orifices providing a smoke barrier in said third passageway whereby smoke passing to said first and second passageways from said third passageway is diverted through said orifices. 